The efficient differentiation of retinal cells from human pluripotent stem cells remains a major challenge for the development of successful and cost-effective cellular therapies for various forms of blindness. Current differentiation strategies rely upon exposing pluripotent stem cells to soluble growth factors which play key roles during early development (such as DKK-1, Noggin and IGF-1) at 20% oxygen (O2). This O2 tension is however, considerably higher than O2 levels during organogenesis and may impair the differentiation process. In this study, we examined the effect of mimicking the physiological O2 tension (2%) on the generation of retinal progenitor cells (RPCs) from human induced pluripotent stem cells (iPSCs) and human embryonic stem cells (hESCs). Both cell types were induced to differentiate into RPCs at 20% and 2% O2. After three days in suspension culture as embryoid bodies (EBs), 2% O2 caused the activation of hypoxia inducible factor (HIF) responsive genes VEGF and LDHA and was accompanied by elevated expression levels of the early eye field genes Six3 and Lhx2. 21 days after plating EBs in an adherent culture, we observed more RPCs co-expressing Pax6 and Chx10 at 2% O2. qPCR analysis confirmed that lowering O2 tension had caused a rise in the expression of both genes compared to 20% O₂. Our results indicate that mimicking physiological O2 is a favorable condition for the efficient generation of RPCs from both hiPSCs and hESCs.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:565553 |
| Date | January 2011 |
| Creators | Bae, D.-K. |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1335614/ |
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